1. Field of the Invention
The present invention relates to a photosensitive composition capable of reacting to change the property thereof upon irradiation with an actinic ray or a radiation, and a pattern-forming method using the photosensitive composition. More specifically, the invention relates to a photosensitive composition for use in a manufacturing process of semiconductors, such as IC, manufacture of circuit substrates for liquid crystals, thermal heads and the like, other photo-fabrication processes, lithographic printing, acid-curable compositions, and also relates to a pattern-forming method using the photosensitive composition.
2. Background Art
Chemical amplification resist compositions are pattern-forming materials capable of generating an acid at an exposed area irradiated with radiation such as far ultraviolet rays, changing the solubility in a developing solution between the irradiated area with the actinic radiation and the non-irradiated area by reaction with the acid as a catalyst, and forming a pattern on a substrate.
In a case where a KrF excimer laser is used as an exposure light source, since resins having poly(hydroxystyrene) small in absorption in the region of 248 nm as a fundamental skeleton are mainly used, a good pattern having high sensitivity and high resolution can be formed as compared with the conventional naphthoquinonediazide/novolak resins.
On the other hand, when a light source of a shorter wavelength, e.g., an ArF excimer laser (193 nm), is used as an exposure light source, even the chemical amplification series resists are not sufficient, since compounds containing an aromatic group substantially show large absorption in the region of 193 nm.
Therefore, resists containing a resin having an alicyclic hydrocarbon structure have been developed for an ArF excimer laser.
As acid generator that is the principal constituent of chemical amplification resist, triphenulsulfonium salts are generally known (e.g., refer to patent literature 1: U.S. Pat. No. 6,548,221).
However, the acid generator is still insufficient in various points, so that photosensitive compositions improved in sensitivity, resolution and defocus latitude (DOF) are desired. Defocus latitude is the latitude of deviation of focus at the time of exposure.